On 6/3/24 16:36, Nathan Chancellor wrote:
On Fri, May 31, 2024 at 11:37:51AM -0700, John Hubbard wrote:
gcc defaults to silence (off) for the following warnings, but clang defaults to the opposite. The warnings are not useful for the kernel itself, which is why they have remained disabled in gcc for the main kernel build. And it is only due to including kernel data structures in the selftests, that we get the warnings from clang.
-Waddress-of-packed-member -Wgnu-variable-sized-type-not-at-endIn other words, the warnings are not unique to the selftests: there is nothing that the selftests' code does that triggers these warnings, other than the act of including the kernel's data structures. Therefore, silence them for the clang builds as well.
This eliminates warnings for the net/ and user_events/ kselftest subsystems, in these files:
./net/af_unix/scm_rights.c ./net/timestamping.c ./net/ipsec.c ./user_events/perf_test.cCc: Nathan Chancellor nathan@kernel.org Signed-off-by: John Hubbard jhubbard@nvidia.com
This seems reasonable to me.
Acked-by: Nathan Chancellor nathan@kernel.org
tools/testing/selftests/lib.mk | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk index 2902787b89b2..c179c02281e9 100644 --- a/tools/testing/selftests/lib.mk +++ b/tools/testing/selftests/lib.mk @@ -50,6 +50,14 @@ else CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%)) endif # CROSS_COMPILE +# gcc defaults to silence (off) for the following warnings, but clang defaults +# to the opposite. The warnings are not useful for the kernel itself, which is +# why they have remained disabled in gcc for the main kernel build. And it is +# only due to including kernel data structures in the selftests, that we get the +# warnings from clang. Therefore, disable the warnings for clang builds. +CFLAGS += -Wno-address-of-packed-member +CFLAGS += -Wno-gnu-variable-sized-type-not-at-end
Thank you for adding this comment block.
CC := $(CLANG) $(CLANG_FLAGS) -fintegrated-as else CC := $(CROSS_COMPILE)gcc -- 2.45.1
Thank you both. I will apply this for the next release. I want this change soaking in next for a bit.
thanks, -- Shuah